APP UART COMMUNICATION ERROR eror code

[aep]

both for APP_UART_FIFO_INIT and APP_UART_INIT i never receive APP_UART_DATA_READY

but at least i get APP_UART_DATA sometimes. most of the times i get APP_UART_COMMUNICATION_ERROR with uart_evt->data.error_communication being either 1 or 4 or 8 randomly.

what is the meaning of the error code there and how can i use it to determine the actual error? The data on the line looks fine in a logic analyzer.

[Ole Bauck]

The uart_evt->data.error_communication is equal to the ERRORSRC register, see here (same for nRF51). You are receiving OVERRUN, FRAMING and BREAK errors which can occur if you are using the wrong baudrate. Have you configured the same baudrate on both sides of the UART?

[aep]

Yeap, My logic analyzer shows its matching up fine. Curiously i receive exactly 5 or 6 characters until i get an error. It sounds like the fifo doesnt actually work and the internal hw buffer is just 6 bytes.

[Ole Bauck]

Sounds like that. Are you using app_uart.c or app_uart_fifo.c? You should use the fifo file. Are you running an example?

[aep]

bah of course i used the wrong file, thanks Ole.

with app_uart_fifo i just get APP_UART_COMMUNICATION_ERROR with error code 4 and no other event.

All of this is with or without flow control btw, but with flow control its a tiny bit better.

[Ole Bauck]

You can get FRAMING or BREAK errors if the transmitting device restarts, could that be the case? Do you get the error often? If you are using the APP_ERROR_HANDLER on the error I would consider changing it to a more suitable error handler, because APP_ERROR_HANDLER will either reset the chip or go into infinite while loop, see here.